@import "compass/css3";
*{margin:0;padding:0;border:0;box-sizing:border-box;
	text-decoration:none;}

#demo {
	// display:block;
	width:402px;
	position:relative;
	margin:50px;
	border:1px solid red;
}
#mark {
	position:absolute;
	width:402px;
	height:257px;
	z-index:10;
	background:#fff;
	@include opacity(0);
}
#small-box {
	position:relative;
	cursor:move;
}
#float-box {
	position:absolute;
	width:160px;
	height:120px;
	background:rgb(204,204,204);
	@include opacity(.5);
	border:1px solid #fff;
}
#big-box {
	position:absolute;
	top:0;
	left:500px;
	width:400px;
	height:300px;
	border:1px solid #ccc;
	overflow:hidden;
	img {
		position:absolute;
	}
}